Nitramines



Patented Oct. 25 1949 I 4' UNITED STATES PATENT OFF-ICE NITRAMINES Alfred T. Blomquist and Fred T. Fiedorek, Ithaca, N. Y., assignors to the United States of America as represented by the Secretary of the Navy No Drawing. Application December 30, 1944,

' "Serial No. 570,806

It will be noted that one of these four nitramines (DINA) contains two nitroxyalkyl groups in addition to a nitramine group. Possibly because ofthe'presence of these nitroxyalkyl groups, DINA is capable of plasticizing nitrocellulose and is therefore of interest :as a replacement for the undesirably volatile nitroglycerine used in propellants of the double base type (of. Wright et 2.1. application Ser. No. 570,813, noW Patent No. 2,461,582, and Kincaid et a1. application ser. 'No.5'70,808,'both filed of even date herewith) DINA, however, tends to crystallize out of the c'olloided nitrocellulose matrix of propellant compositions. For this and other reasons, DINA in itself is :not entirely unobjectionable as a nitrocellulose plasticizer for use in propellant compositions.

Broadly speaking, the object'of the present invention is to provide a new series of nitramines containing a nitroxyalkyl group in'addition to'one ormore nitramino groups.

-A further object is the provision of a novel series of nitroxyalkylnitramines suitable for various industrial uses but of particular interest in connection with the manufacture of industrial and military explosives.

A more particular object is to provide anew series ='of nitroxyalkylnitramines that are capable of plasticizing nitrocellulose, and are therefore adaptable for use in the production of propelhints.

Another-object is to provide commercially feasible methods for the synthesis of such compounds.

'Still turther obiect's'and advantages will be apparent as theinvention is hereinafter more fully described.

The nitramines with which the present invention-is primarily concerned comprise a novel class of compounds havin the general structural formula:

I J-ONOQ NO2N/ l where X is either hydrogen or alkyl or carbalkoxy.

More particularly, the nitramines of the present :nitramino-alkyl and R is either hydrogen, alkyl or carbalkoxy. Such compounds are of interest as plasticizers for nitrocellulose. Moreover, because of the relatively low volatility of many of the class members, they provide a series of relatively non-volatile explosive or semi-explosive compounds adaptable for use in the preparation of propellants.

The novel nitro'iwalkylnitramines of the present invention may conveniently be classified into two subclasses, namely (1') those wherein the R radical is hydrogen or'carbalkoxyl; and (2) those wherein the R radical is alkyl. The first subclass (R =H or --COOR) may be prepared from the appropriate primary alkanol amine whereas the second subclass (R =alkyl) may be prepared from the appropriate secondary alkanol alkyl amine.

The synthesis of the first subclass may be illus- 0 trated by the following series of reactions:

3 The synthesis of the second subclass of nitramines (R or R =alkyl) may be accomplished somewhat more readily by the catalytic dehydration of the corresponding nitroxyalkylamine nitrate salt, as illustrated by the following equations:

41 R-NH-CHgCHr-OH R-NHt-CHiCHgONOj R-NH:CH|CH|ON0| 011,0 o ,o NO; 201- or Br) Before describing in detail the procedures used for preparing the various nitramines of the present invention, a brief description of the preparation and properties of several specific compounds in this series may be of interest. Purely as a matter of convenience these will be discussed as members of a homologous series, the parent compound of which is N-(2-nitroxyethyl)nitramine,

NO2-NHCH2CH2ONO:

hereinafter referred to by the trivial name, NENA. The N-alkyl homologues (R =alkyl) of this parent compound may conventently be designated Alkyl-NENAs, the N-methyl homologue being called Me-NENA, the N-ethyl homologue, Et-NENA, etc.

N-(Z-m'troxyethyl)nitramine (NENA) and the corresponding urethane R and R are H; R is either H or CO0C2H5.

Of interest from a standpoint of explosive properties, because it possesses a structure interme- 4 diate to glycol dinitrate and ethylenedinitramine is the compound N-(2-nitroxyethyl)nitramine (NENA") having the following formula:

This substance is a liquid at room temperature and melts at 15 C. Its explosive properties are as follows:

Oxygen balance to CO2: -15.9%.

Explosion temperature: No explosion, 360 C.;

volatilizes rapidly.

Thermal stability (135 C.) Acid in 75 min.

Power: 133.9 (TNT=100).

Impact sensitivity (50% pt.) 191, 107 cm.

The synthesis of NENA may be carried out according to the following equations:

N-(2-ethanol)urethane was obtained from ethanolamine and ethyl chlorocarbonate by employingv a modification of the method used by Franchimont and Lublin, Rec. trav. chem. 21, 48 (1902). Yields as high as 96 per cent of theoretical were obtained. The nitration of N-(2-ethanol) urethane proceeded smoothly and ammonolysis of the resulting nitrourethane yielded the ammonium salt of N-(2-nitroxyethyl)nitramine in yields of 97 per cent. This salt decomposition proceeded more rapidly in aqueous solution and because of this, the isolation of N-(2- nitroxyethyDnitramine by the neutralization of the ammonium salt is preferably carried out as rapidly as possible. By this technique, yields of 93.3 per cent of the theoretical were realized for the free nitramine.

N- (Z-nitroxyethyl) methylnitramine (M e-NENA) R1 R2 cn-t in-oNoi R and R. are H; R is methyl.

With a view to developing an essentially nonvolatile nitrocellulose plasticizer for use in double base-type powders in lieu of nitroglycerine, the preparation of N-(Z-nitroxyethyl)methylnitramine was undertaken.

The properties of Me-NENA are as follows:

M. P., 38-40 0. Oxygen balance to CO2: -43.6%. pH: 7.2. Explosion temperature: No explosion 360 C. Thermal stability (135 0.): Volatilizes rapidly;

acid in min. Vacuum stability (100 C.): 6.30; 7.38 cc./5 g./48

hrs. International test C.) Volatility, 0.13%;

0.10%. Hygroscopicity:

R. H.: 0.00%. R. H.: 0.01%. Power=135.5; 137.2 (TNT=100). Impact sensitivity: Greater than 90 cm. (Cyclonite=4850 cm.). Density (by picnometer) Liquid: D4 =1.40. Solid: D4 =1.53.

'Me-NENA may be prepared from methyl ethanolamine by the reactions shown in the following equations:

This preparation may be carried out in one stage by adding N-methyl-2-ethanolamine and nitric acid concurrently and simultaneously to acetic anhydride containing a trace of chloride catalyst. If preferred, however, the process may be carried out in two-stages, one of which involves the formation of a solution of the amine and nitric acid, while the second involves the addition of this solution to the acetic anhydride and the chloride catalyst. The Me-NENA is separated from the reaction mixture produced by either the one-stage or the two-stage process by diluting the mixture with water, and then filtering ofi the Me-NENA precipitate from the mother liquor.

Stability of Me-NENA posed slowly at room temperature. The decom- 75 stability of Me-NENA. The vacuum stabilitles of mamas Vacuum stability of Me-NENA, DINA and nitroglycerine at 100 0.

Sample Time (hr-s.)

Me-NENA 144, 144. DINA 10, 42. N. G 12%, 1234.

' e 2.4 g. samples were used in these tests. The time represents th number of hours required to exceed the capacity of the 'apparatu N (Z-nitromyethyl) ethylnitram'ine (Et-NENA R and R are H; R is ethyl.

-A nitroxylalkyl nitramine homologous to N-(2- i nitroxyethyhnitramine, (NENA), and N-(2-nitroxyethyl)methylnitramine (Me-NENA) is the compound N-(2-nitroxyethyl)ethylnitramine or Et-NENA. This substance was prepared by a process indicated by the following equations:

N -(2-nitrocypropyl) nitramine (Is'o-Me-NENA) and the corresponding urethane R is H; R is methyl; R is H or --COOC2H5.

Another nitroxyalkylnitramine related to N-(2- nitroxyethyDnitramine (NENA') is N- (Z-nitroxypropyl) nitrarnine (iso-Me-NENA). compound is isomeric with N -(2-nitroxyethy1') methylnitramine (Me-NENA) difieringfi'om it'only in the position of the methyl group. Its synthesis was carried out as indicated by the following equations:

I HNO 7 omoncm-mrcoon --f omoEoHhN-coon H No, no;

omoHcm-m-ooon onacncm NnNoi' then H01 N02 N05 N07 N-(Z-propanoDurethane was converted into the corresponding nitroxyalkyl nitrourethane by treating it with an excess of 98 per cent nitric acid. N- (Z-nitroxypropyl) nitrourethane is soluble in ether and when the extract was treated with dry ammonia the ammonium salt of N-(2- nitroxypropyl) nitramine was obtained as an oil which solidified upon standing a short while. The free nitroxyalkylnitramine was obtained simply by acidifying an aqueous solution of the ammonium salt.

N- (Z-nitromyethyl) butyln'itramz'ne (Bu-NENA) RIRZ No,-N eH-oH--o-N0,

R and R are H; R is n-butyl.

The butyl homologue (Bu-NENA) of Me-.-NENA may he obtained from Z-ethanol butylamine ,by the reactions indicated by the following equav A o 4 N-(z nitrozcyethyl)cyc'lohemylnitramine The cyclohexyl homologue of Me-NENA-may be prepared from cyclohexylethanolamine by the reactions indicated by the following equations:

HNOav C;H11NHCH,CHOH v cgmr-Nm-omomoNo,

I NO: i 0020 I 5 OlHlr-NHZ-CHICHjONOl C1 C|H11N-CH|CH:ONO|

N03 2-nitramino-ll-butanol nitrate and corresponding urethane R1 R N( JCH1ON0 R and/or R is H, CH3, or C2H5; R is H or CO2C2H5.

Another compound related to NENA is obtainable by nitration of N-carbethoxy-Z-amino-lbutanol. This urethane was obtained from Z-amino-l-butanol and chloroethyl carbonate. A similar compound (R and R =rnethyl) may be obtained from 2-amino-2-methy11-propanol via the urethane.

Dinitraminoisopropyl nitrate and the corresponding urethane --CHzNHNO2; 1'1. is H or -COC2H5.

The synthesis of dinitraminoisopropyl nitrate was carried out according to the following:

The latter compound is a nitramino analogue of nitroglycerine wherein two nitroxy groups are replaced by two nitramino groups. Its explosive properties are as follows:

1!. P.: 164-154 (decomp.). Oxygen balance to CO2: 17.8%. pH: 3.5. Explosion temperature; Deflagrated, 230 C. Thermal stability:

100 0.: not acid in 300 min. 135 0.: acid in 105 min. Vacuum stability-100 0.: 1. 99, 4.36 cc. in 48 hrs. International test (75 0.): 0.0%. Hygroscopicity:

90% R. H.: 0.02%. 100% R. H.: 0.02%. Power: 141.5 (TNT=100). Impact sensitivity: 24.4 cm. (Cyclonite=48-50 3-nftro-4,4-bis(nitrorymethyl) orazolidone A cyclic urethane related to the urethane from which NENA was prepared is 3-nitro-4,4-bis(nitroxymethyboxazolidone, having the structure:

31 R: t-Jmorro:

NOr-

where R is nitroxymethyl; RF is H; and R. is the cyclic urethane group, COOCH2-.

This compound was prepared from trimethyl aminomethane, (Commercial Solvents Corporation) by the following series of reactions:

(c) omoNo, cmoiio,

o-onloNo, ':orr,oNo, HNO H GB: Og-N CH! a) omen 011,0N0.

CH2OH BN0 mrro, an on, NOg-N 0H,

H18 04 o 0 o o In order more clearly to describe the new and improved nitramines of the present invention several specific examples will hereinafter be described in considerable detail. It should be clearly understood, however, that this is done solely by way of example, and not for the purpose of delineating the scope of the invention or limiting the ambit of the appended claims.

EXAMPLE I Preparation of N (2 nitroxyethybnitramine (NENA) and N (2 nitroxyethybnitrourethane R and R are H; R is H or --COOC2H5.

A. Preparation of N-(Z-ethanol) urethane In a three-liter, three-necked flask provided with a mechanical stirrer, thermometer, and two dropping funnels there were placed 244 g. (4.0 moles) of ethanolamine, 600 cc. of water, and 750 cc. of ether. The reaction mixture was cooled to 510 C. (external cooling) and 217 g. (2.0 moles) of ethyl chlorocarbonate was added slowly with stirring. The temperature of the reaction mixture was maintained at 5-10 C. during the addition. Following this addition there was added simultaneously 217 g. (2 moles) of ethyl chlorocarbonate and a solution of 160 g. (4 moles) of sodium hydroxide in 400 cc. of water. When the addition was complete, 500 cc. of ether was added and the reaction mixture stirred for one-half hour. The ether layer was separated and the aqueous solution was extracted with eight -cc. portions of ether. The combined ether extracts were dried with anhydrous magnesium sulfate and the ether removed by distillation. The residue was distilled under reduced pressure. There was obtained 510 g. (96% yield) of the colorless liquid urethane; b.p. 132-134" at 5 mm.

B. Nitration of N-(Z-ethanol) urethane The nitration of N-(2-ethanol)urethane was carried out in a 1000 cc., three-necked flask equipped with thermometer and stirrer. After adding 250 cc. of 98 per cent nitric acid to the flask and cooling to 5 C., 50 g. (0.376 mole) of N- (2-ethanol) urethane was added dropwise. The temperature of the reaction mixture was maintained at 510 C. during the addition. After stirring for fifteen minutes the reaction mixture was poured over 750 g. of cracked ice. The product separated as an oil and was extracted with three 250-cc. portions of ether after the mixture had been neutralized with sodium bicarbonate. The ether extract was dried rapid- C. Ammonolysis' of N-(Z-nitroxyethybnitrourethane The ammonolysis of N-(2-nitroxyethyDnitrourethane was carried out using the ether solution that was prepared above. The ammonium salt of N-(2-nitroxyeth-yl)nitramine was isolated employing the following procedure. Dry ammonia was bubbled through the dried ether solution, keeping the solution cool with an ice-water bath, until the ether was saturated. The ammonium salt of N-(2-nitroxyethyl) nitramine precipitated and was filtered and washed with dry ether. The product (61.3 g., 97% yield) melted with decomposition at 78-79 C.

The ammonium salt of. N-(2-nitroxyethyD- nitramine decomposes slowly at room temperature- The decomposition of the salt proceeds more rapidly in aqueous solution.

D. Isolation of N- (Z-nritroxyethyl) nitramine (NENA) The ammonium salt of N-(2I-nitroXyethyl) nitramine (61.3 g., 0.365 mole) was dissolved in 250 cc. of ice water and immediately neutralized to Congo Red by adding concentrated sulfuric acid (10.3 cc.) dropwise with. stirring. The oil which separated was extracted with three portions of ether (150, 100, and 100 cc.) and the combined extracts were dried over 25 g. of anhydrous magnesium sulfate. The ether was removed from the dried solution byvacuum distillation at room temperature. The last traces of ether were removed by heating to 100*" C. at i9 mm. The product was a pale yellow, water-insoluble oil melting at 15 C. The yield (51.4 g.) was 93.3 per cent of the theoretical amount.

Titration with standard alkaligave an equivalent weight of 155'. Calculated equivalent weight for N- (2-nitroxyethy1) nitrami'ne is 151.

Analysis: Calcd. for C2H505N32 Found: N, 27.52, 27.64, 27.23, 27.36.

Because of the speed with which the ammonium salt of N -(2-nltroxyethyl) nitramine decomposes in aqueous solution, acidification of the cold aqueous solution with sulfuric acid should be carried out as quickly as possible. In one experiment the aqueous solution of. the ammonium salt was cooled to -10 C. and acidified immediately, giving a 95 per cent yield of the nitramine. In another experiment the acidification was. carried out at room temperature and gave a 76 per cent yield. Finally in a third experiment the aqueous solution of the salt was allowed to. stand at room temperature for one hour before acidifying. In this case the yield fell to 61 per cent. A considerable evolution of gas: accompanied the acidification in the last experiment.

The compound, N-(Z-nitroxyethyl)nitramine, should be handled carefully as it appears to be a skin irritant. It produces inflammation and itching.

E. The silver salt of N-(Z-nitroxyethyl) nitramine An aqueous solution of 42.5 g. (0.25 mole) of silver nitrate in 500 cc. of water was added with stirring to a solution of 42. g. (0.25 mole) of the ammonium salt of N-(2-ni'troxyethyl)nitramine. A gummy precipitate separated which solidified to a chalky white solid. After filtering, the product was washed with water, alcohol and ether. The solid product (62.0- g., 96.1 per cent yield) de- I0 composed when heated to about 120 C. darkens on exposure to light.

Analysis: Calcd. for C2I-I4O5N3Ag: N, 16.29; Found: N, 16.28, 16.49.

EXAMPLE II Preparation of N-(z nitroxyethyl) methylnitramine (Me-NENA) R1 R1 t CH- H-ONO:

R and R are H; R is methyl.

A. One-stage preparation of Me-NENA In a 1000-00., three-necked flask fitted with stirrer, thermometer, and dropping funnel there was placed 245 g. (2.4 moles) of acetic anhydride. While maintaining the temperature at 10-12 C. by means of external cooling, 126 g. (2 moles) of nitric. acid (98 per cent) was added with vigorous stirring. After addition of the acid, 6.0 g. (0.044 mole) of anhydrous zinc chloride was added.

To the nltrating mixture there was added 75 g. (1.0 mole) of methylethariolamine through. a

capillary-tipped dropping funnel whose end was immersed below the surface of the nitrating solution. During the addition which required two hours the temperature was held at 10-12 C. After all of the amine had been added the charge was stirred for an additional period of one hour at the same temperature followed by stirring for half an hour at 40 C. The contents of the flask were poured on 500 g. of cracked ice. A precipitate of N-(Z-nitroxyethyl) methylnitramine separated and was filtered and washed with two -cc. portions of water.

The crude product (111.6 g.) melting at 36.5-38 C. was recrystallized from 1000 cc. of anhydrous ether and gave 93.8 g. of a crystalline solid melting at 39-40.5 C. (corn). An additional 9.4 g. of product was obtained upon concentrating was 63 per cent.

B. Two-stage preparation of Me-NENA N-(2-nitroxyethyl)methylnitramine has been prepared by treating N-methyl-2-ethanolamine dinitrate with acetic anhydride,, zinc chloride, and hydrochloric acid at 40 C. The intermediate dinitrate is a crystalline salt and is best obtained by adding N-methyl-Z-ethanolamine to 98 per cent nitric acid and pouring the reaction mixture into ether.

1. Preparation of N-methyZ-Z-ethanolamine dinitrate.In a 200 cc., three-necked flask provided with stirrer, thermometer, and dropping funnel, there was placed 45 cc. (1.07 moles) of 98 per cent nitric acid. While maintaining the temperature of the reaction below 25 C., there was added slowly through a capillary tipped dropping funnel, whose end was immersed below the surface of the acid, 7.5 g. (0.1 mole), of N-methyl-2- ethanolamine. The reaction was stirred for one hour and then added dropwise to 500 cc. of ether While employing vigorous stirring. A crystalline precipitate formed which was filtered off and washed well with ether. There was obtained a solid (17.5 g.) melting at 76-8 C. No further purification was necessary preparatory to the next step. Yield, 95 per cent.

2. Conversion of N-methyl-Z-ethanolamine dinitrate into N-(Z-nitroxyethyl)methylnitra- 11 mine.-A mixture of 100 cc. of acetic anhydride, 1 g. of zinc chloride and 1 cc. of concentrated hydrochloric acid was warmed to 40 C. To the solution there was added in portions 17.3 g. (.095 mole) of N-methyl-2-ethanolamine dinitrate while maintaining the same temperature. After stirring for minutes the reaction was poured into 500 cc. of water. After a short time complete miscibility occurred and when the acid was neutralized with a calculated amount of sodium 1.

bicarbonate a precipitate formed which was filtered oil and washed well with water. There was obtained a crystalline solid (10 g.) melting at 38-40 C. After one recrystallization from ether the melting point was unchanged.

C. The stabilization of Me-NENA A 200 g. sample of crude Me-NENA (M. P. 36.537.5 C.) was suspended in 800 cc. of water containing 8 g. of sodium bicarbonate and steam bubbled into the mixture until the temperature had risen to 75 C. The charge was then agitated by bubbling air through the suspension until the temperature had dropped to 50 C. The agitation was continued and pieces of ice added until precipitation occurred. The Me-NENA was separated and the entire process of steaming, agitation and cooling was repeated and the product finally filtered.

The solid obtained was dissolved in 400 cc. of acetone, then cooled in an ice bath, and three liters of water added dropwise to the acetone solution. Further cooling and vigorous stirring 12 necked flask. Moderate stirring was employed and the reaction was maintained at 35 C. After the addition of the amine-nitric acid mixture which required fifteen minutes, the reaction was kept at 35 C. for an additional fifteen minutes. After pouring the contents of the flask into 550 cc. of ice and water there was obtained an oil were employed. When the mixture became milky it was seeded to induce crystallization. product was filtered by suction, air dried, and the final traces of moisture were removed by drying in vacuo over phosphorus pentoxide for 24 hours. The product (161 g.) melted at 39-40 C.

An 80 g. sample of Me-NENA was recrystallized from 720 cc. of ether using vigorous stirring and COOllIlg in an ice bath. After filtration there was obtained 74.8 g. of product melting at 39.5"- 40.5 C.

The ether recrystallized Me-NENA was analyzed.

Analysis: Calcd. for CsH'iOsNs! C, 21.82; H, 4.27, N, 25.45. Found: C, 21.74; H, 3.79; N, 24.49; 24.68.

EXAMPLE III Preparation of N (Z-nitromyethyl) ethylnitramine (Et-NENA) R and R are H; 1'1. is ethyl.

Into a 500 cc., three-necked flask containing 67.7 g. (1.05 moles) of 98 per cent nitric acid and equipped with stirrer, thermometer, and a capillary tipped dropping funnel whose end was immersed below the surface of the acid, there was added 44.5 g. (0.5 mole) of ethyl ethanolamine. The contents of the flask were cooled externally and the temperature maintained below 10 C. during the addition.

The amine-nitric acid mixture was transferred to a dropping funnel and added dropwise to a solution of 118 g. (1.1 moles) of 95 per cent acetic anhydride and 0.86 g. (0.011 mole) of acetyl chloride contained in a 500 cc., three- The which was separated and washed successively with two 100 cc. portions of 5 per cent sodium bicarbonate and two 100 cc. portions of water. After filtering, the pale yellow oil was dried by bubbling dry air through it. There was obtained 73.4 g. (82 per cent of theoretical) of N-(2-nitroxyethyl)ethyl-nitramine melting at 4-5.5 C.

Theoretical molecular refraction=38.75. Observed molecular refraction=38.4.

EXAMPLE IV Preparation of N- (Z-nitroxypropyl) methylnitramine (MezNENA) R =H; R and R are methyl.

Into a 500 cc., three-necked flask equipped with stirrer, thermometer and a capillary tipped dropping funnel whose end could be immersed well below the surface of the reaction mixture there was placed 67.7 g. (1.05 moles) of 98 per cent nitric acid. To this there was added by means of the dropping funnel 44.5 g. (0.5 mole) of 2-hydroxypropylmethylamine. The contents of the flask were externally cooled to a tempera- .ture below 10 C. and there maintained during the addition.

The amine-nitric acid mixture was transferred to a dropping funnel and added dropwise to a solution of 118 g. 1.1 moles) of per cent acetic anhydride and 0.86 g. (0.011 mole) of acetyl chloride contained in a 500 cc., three-necked flask. Moderate stirring was employed and the reaction was maintained at 35 C. After the addition of the amine-nitric acid mixture which required fifteen minutes, the reaction was kept at 35 C. for an additional fifteen minutes. After pouring the contents of the flask into 550 cc. of ice and. water there was obtained an oil which was separated and washed successively with two 100 cc.

portions of 5 per cent sodium bicarbonate and two 100 cc. portions of water. After filtering. the pale yellow oil was dried by bubbling dry air through it. There was 65.8 g. (74 per cent of theoretical) of N-(2-nitroxypropyl)methylnitramine as a pale yellow oil, melting at 22-23 C.

Theoretical molecular refraction=38.75. Observed molecular refraction=38.5.

EXAMPLE V Preparation of N-(Z-nitroxypropyl)nitrourethane and N-(Z-nitroxypropyl nitramine ("iso- M e-NENA) R is H; R. is methyl; R is --COOC2H or H.

A. Preparation of mammary-1 -amino-2- propanol a concurrent addition of 54.3 g. (0.5 mole) more ethyl chlorocarbonate and asolution (if-'40 g; (1.0

mole) of sodiumhydroxide in. 100 cc. of water. Vigorous stirring was. employed throughout the addition. After stirring for an additional onehalf' hour, the. ether extract: was separated. The aqueous solution was extracted with three portions of ether (200, 200, and 100 cc.). The combined extract was dried with magnesium sulfate and then distilled to remove the ether. The oily residue was distilled at reduced pressure. There was obtained a clear liquid (127.4 g.) boiling at 1075-110 C'./1 mm. Yield, 87 per cent.

Theoretical molecular refraction=36.4,6. Observed=36.4.

B. Nitration of N-carbethozcy-I-amino-Z- propanol In a two-liter, three-necked flask provided with stirrer, thermometer, and dropping funnel there was placed 735 cc. (17.5 moles) of 98 per centnitric acid. While employing moderate stirring and maintaining a temperature of 10 by external cooling, there was added dropwise 147 g. (1.0 mole) of N-carbethoxy-1-amino-2- propanol. After completion of the addition the reaction was maintained at 10 for one-half hour and then poured over 3700 g. of ice and water. The excess acid in the mixture was neutralized with 1310 g., of sodium bicarbonate and the product extracted with two portions (750 750 0.0:) of ether. The extract was dried with anhydrous magnesium sulfate and used directly in the-next step.

C. Ammonolysis o1 N-(Z-nitromypropybnitrourethane; isolation of N-(Z-nitroxypwpyllnitramine The dried ether solution of the nitroxyalkyl nitrourethane was cooled in an. ice bath and saturated with dry ammonia. An oil separated, which on, standing, solidified to, a. White crystalline solid, the ammonium salt of N-(Z-nitroxyprO- pyl) nitramine. The. salt was. filtered and washed with several portions of dry ether.

The ammonium salt. obtained in. the ammonolysis was dissolved in one liter of ice water andneutralized t0 Congo red with concentrated hydrochloric acid. The nitroxyalkylnitramine precipitated" instantaneously and after filtering; the solidwaswashed with two 100 cc. portions of water. There wasobtained 18311 g. (81 per cent of the theoretical) or a N-(Z-nitroxypropyDnitramine melting at 84-85 C. The product was recrystallized once fromether and for the final purification it was precipitated from acetone by the addition of water. The melting point of purified product was 86-87"- C.

Analysis: Cal-ed. for C3H7O5N'3: C, 21.82; H, 4.27 N, 25.45; neutral equivalent, 1651. Found: C,- 21'.54;-H. 4.04; N, 24.40, 24.70;- neutral equivalent, 165.

EXAMPLE Preparation of N Z-nitroxyethyl) butulnflmflm. (Bu-NENA) R1 2 ()H-(BHONO:

NOPN.

R and R are H; R is butyl.

The nitration of N-nebuty lmomethano mm. (Sharples) was carried. out by a...modiflcatlnn 01" the procedure described in ExampleII torthe one-step preparation of Me-NENA.

Acetic anhydride (610 g). 98.3%. nitric; acid. (207.5 cc.) and zinc chloride (15 g.) weremixed" in a covered stainless steel beaker and cooled to 10-13 C. The mixture was stirredmcchaninly and 230 g. (B. P. 109.5:0.5 C./27 mm.) wasaddedunden the surface of the liquidthrough adroppinanel with a constricted tip. The aminewas: troduced over a period of one and one-hall" hours, while the temperature was-maintained at 10-13 C. The solution was furtherstirred at 13 C. for half an hour and thenfor'haltanzhm' at 40-45" C. The nitration mixture: was drowned. in excess ice water. The pale yellow. oilwhich separated was washed thoroughly: with waten; with aqueous bicarbonate solution: and than:

steamed by agitating the material violently with live steam at 100 C. for 15- minutes. Finally the; Butyl-NENA was washed twice with-water; dried: over calcium chloride and filtered; yield oi" purified product was 370 g. (9-1 percentottheoryiz. It froze at 9.9 C. and melted at; 9.1"- (21;; n -1.4750.

Analysis by nitrometer: Nitrate-N calc; $.73; found, 6.68.

EXAMPLE VH Preparation of N- (Z-nitromyethylicyclohezylrrih Into a 200ml. flask fitted with stirrenthermometer, addition funnel, and outsidecoolinev than. was placed 27.1 grams of 98.5% nitricacid; 'l'q. this: was added, with stirring; at 1045" 1H; grams of pure cyclohexylmonoethanolamine... This melts at39 C., was warmedprior-togadditdm. andthen added to the nitric: acid, intheiormpfii'a. supercooled liquid.

The nitric acid solution, thus prepared.

transferredto an addition funnehand thenaddeit. to a stirred mixture of 47.2, gramsot w anhydride and 0.3' gramsof: powdered zinc chloride in. a 200 m1. flask, whileymalntatningr the temperature in the flask at 35" C. when addition was complete, stirring was continnedi'iofi minutes at 35 to 40 C.

The nitration, mixture was-thendrowned im anexcess of chipped ice. A crystalline productawaa: thus formed. This was removed by'flltratwn, washed with cold water, washed with hot water (which caused the product to melt)*. cooled, filtered, washed again, with cold water and dried in a vacuum desiccator over calcium chlorides The yield was 10 grams (43% of theoretical) of pale yellow crystals, M. P. 3610-363?" C. Thissmay. be recrystallized from an acetone-Ilgroin mix,

78 ture to yield white crystals, M. P. 37.8-38.4 C.

of purified butylmonoothanollmina H 15 EXAMPLE VIII (A) R is ethyl; R is H; R2 is H; R3 is '-,COOC2H5; and (B) R1 and R1- are methyl;

RF is H; R3 is 'COOC2H5.

A. Preparation of N -carbethomy-Z-amino-I-ba- I tanol -,Into acne-liter, four-necked flask fitted with stirrer, thermometer, and two dropping funnels, there was added 89 g. (1.0 mole) of 2-amino-1- butanol, 150 cc.-of water, and 200 cc. of ether. After cooling thecontents of the flask to 510 0., and maintaining this temperature, 54.3 g. (0.5 mole) of ethyl chlorocarbonate was added dropwise. Next there was added concurrently a solution of 40 g. (10 mole) of sodium hydroxide in 100 cc. of water and 54.3 g. (0.5 mole) more ethylchlorocarbonate. Vigorous stirring was employed throughout the addition. The reaction was stirred one-half hour. After separation of the ether layer, the aqueous solution was extracted with two portions of ether (200 and 200 00.). The combined extract was dried with 80 g. ofmagnesium sulfate. The extract was concentrated through distillation until a thick oil remained. Upon standing the oil crystallized. The crude product weighed 147 g. After two recrystallizations, the first from benzene, and the second from ether, the product (68 g.) melted at 54-5 C. (yield 42 per cent). The substance can also be distilled at reduced pressure. It boils at 115-417 C./2 mm.

Analysis: Calculated for C'1H15O3N: C, 52.15; H, 9.38; N, 8.69. Found: C, 51.98; H, 9.44; N, 8.40.

B. Preparation of N-carbethoxy-Z-amino-Z- methyZ-Z-propanol In a one-liter, four-necked flask provided with stirrer, thermometer and two dropping funnels, there were placed 89 g. (1.0 mole) of 2- amino-Z-methyl-l-propancl, 150 cc. of water, and 200 cc. of ether. While maintaining the temperature at -10" C. there was added drop wise 54.3 g. (0.5 mole) of ethyl chlorocarbonate. Then there were added concurrently a solution of 40 g. (1.0 mole) of sodium hydroxide in 100 cc. of water and 54.3 g. (0.5 mole) additional ethyl chlorocarbonate. After the addition the reaction was stirred for one-half hour. The ether was separated and the aqueous layer extracted with the two portions (200, 100 cc.) of ether. After drying the combined extract, the ether was removed by distillation. The residue was distilled at reduced pressure. There was obtained anoily liquid (141 g.) boiling at 97-97 C./2 mm. Yield, 88 per cent.

D4 =1.066, no: 1.451

Observed molecular refraction, 40.7; calculated, 41.1.

Analysis: Calculated for CZH1502NI C, 52.15; H, 9.38; N, 8.69. Found: C, 51.74; H, 9.42; N, 8.12.

' in 500 cc. of water.

16 EXAMPLE 1x Preparation of the dinitrourethane of diaminoisopropanol nitrate and dinitraminoisopropyl nitrate R is H; R is CH2NHNO2 or -CH2N(NO2) COOCzHs and R is H or --COOC2H5 A. Preparation of dinrethane of diaminoisopropanol In a 2000 ccL, three-necked flask fitted with a mechanical stirrer, thermometer, and two dropping funnels, there were placed 45 g. (0.5 mole) of diaminoisopropanol (M. P. 45-57 C.), cc. of water, and 400 cc. of ether. The mixture was cooled to 0-5 C. by means of an ice-salt bath. To the vigorously stirred mixture there Was added dropwise 54.8 g. (0.5 mole) of ethyl chloroformate over a period of one hour. Following this addition, a further quantit of ethyl chloroformate (54.8 g.) and a solution of 40 g. of sodium hydroxide in 100 cc. of water were added separately and concurrently during one hour. After the addition, stirring was continued for two hours at 0-5 C. The ether layer was separated and the water layer extracted With three 100-cc. portions of ether. The ether solutions were combined and dried over anhydrous magnesium sulfate. After removal of the ether by distillation under vacuum there was obtained 118 g. of a yellow viscous residue. All attempts to crystallize the urethane failed. Also, it could not be dis tilled at a pressure of 1.5 mm.

B. Nitration of the diurethane of diaminoisopropanol One hundred grams of the crude diurethane prepared as described above was added to 500 cc. of nitric acid (98 per cent) contained in a 1000- cc. flask over a fifteen minute period. The re-- action mixture was held at 0-5 C. and stirred during the addition of the urethane. After the addition, the mixture was stirred for half an hour and then poured over 2,000 g. of cracked ice. A colorless gummy precipitate was obtained which was separated by decantation, washed with water, and dissolved in ether. The ether solution was washed first with dilute sodium bicarbonate solution then with water and finally dried over anhydrous magnesium sulfate.

C. Isolation of dinitraminoisopropyl nitrate The dried ether solution containing the nitraction product of the diurethane was treated with anhydrous gaseous ammonia at 5-10 C. A gummy precipitate was formed which was separated by decantation, washed with ether, and dissolved The aqueous solution was filtered and acidified to Congo red with dilute hydrochloric acid. The colorless crystalline precipitate was filtered, washed thoroughl with water and dried in the air. The product (71.8 g.)

' melted with decomposition at 161-163 C. (corn).

One recrystallization from 600 cc. of nitromethane gave 56.3 g. of a product melting at 164-165 C. (corn) with decomposition. The overall yield from diaminoisopropanol was 74.8 per cent.

1 7 Analysis of the silver salt:

Calcd. for CHzN(Ag)NO2: N, 15.95; neutral equivalent, 112.5.

CHONOz CHz-N (Ag) N02 Calcd. for CHz-N(Ag)NO2: N, 14.22; neutral equivalent, 90.0. CHOH CHzN(Ag) N02 Found: N, 15.67, 15.27, 15.31; neutral equivalent,

EXAMPLE X Preparation of 3-nitro-4,4-bis(nitroxymethyl) omazolidone R1 3OH ONO NO2-N R is nitroxymethyl; R is -COOCH2 A. Preparation of 4,4-dimethylol omazolidonez reaction of trimethylol aminomethane with ethyl chlorocarbonate Into a. one-liter, three-necked flask provided with a stirrer, thermometer, and two dropping funnels there were added 121 g. (1.0 mole) of trimethylol aminomethane and 200 cc. of water. While maintaining the temperature at 510 C., 54.3 g. (0.5 mole) of ethyl chlorocarbonate was added dropwise. Next there were added concurrently 54.3 g. (0.5 mole) additional ethyl chlorocarbonate and a solution of 40 g. (1.0 mole) of sodium hydroxide in 360 cc. of water. The temperature was allowed to rise to room temperature and the stirring was continued overnight. The solution was distilled at reduced pressure until almost all of the water was removed and the residue was taken up in absolute alcohol. The inorganic salts were filtered off and the alcoholic filtrate was concentrated at reduced pressure. The oily residue was dissolved in 125 cc. of methyl alcohol and cooled overnight. The crystalline deposit was filtered off, washed with 50 cc. of cold methyl alcohol and again with ether. There was obtained a solid (40.0 g.) melting at 108-9 C. By Working up the filtrate and again recrystallizing, an additional 28.1 g. of 4,4-dimethylol oxazolidone was obtained. Yield, 46 per cent.

Analysis: Calculated for C5H9O4N: C'. 40.82; H, 6.12; N. 9.52. Found: C, 40.73; H, 5.57, 5.72; N, 9.64, 9.85.

B. Preparation of 4,4-bis(nitroxymethyl) oxazolidone In a 200 cc., three-necked flask fitted with stirrer and thermometer there was placed 62.5 cc. (1.49 moles) of 98 per cent nitric acid. While maintaining the temperature at 5-10" C. there was added in portions g. of 4,4-dimethylol oxazolidone. After stirring at this temperature for two hours, the reaction was quenched by pouring over 250 g. of cracked ice. A white crystalline precipitate separated which was filtered off and washed with two 50 cc. portions of water. A small additional quantity of the same substance was recovered by neutralizing the acid filtrate with sodium bicarbonate. The combined product was recrystallized from 35 cc. of methyl alcohol. There was obtained 4,4-bis(nitroxymethyl) oxazolidone (11.0 g.), melting at 106-7 0.

5 Number 18 Analysis: Calculated for CtHqOsNs: C, 25.40; H, 2.95; N, 17.72. Found; C, 25.57, 25.39, 25.89, 25.86; H, 3.46, 3.25, 3.28, 3.27; N, 17.59, 17.54.

C. Preparation of 3-nitro-4,4-bis(nitroxymethyl) oscazolidone A nitrating mixture was prepared by adding 62.5 cc. (1.5 moles) of 98 per cent nitric acid to 62.5 cc. (1.17 moles) of concentrated sulfuric acid. After cooling the mixed acid to 510 C., 10 g. (0.068 mole) of 4,4-dimethylol oxazolidone was added in portions, maintaining the same temperature. After the addition the temperature was raised to 50 C. and held there for one-half hour. After cooling, the reaction was poured over 350 g. of cracked ice. A precipitate was formed which was filtered and washed with two 50 cc. portions of water. After recrystallizing the resultant solid from 150 cc. of methyl alcohol a crystalline substance (4.9 g.), 3-nitro-4,4-bis(nitroxymethyDoxazolidone, melting at 122-3 C. was obtained. Yield, per cent.

Analysis: Calculated for CsI-IsOmN4: C, 21.28; H, 2.13; N, 19.86. Found: C, 21.25, 21.35; H, 2.12, 2.01; N, 19.49, 19.38.

D. Conversion of 4,4-bis(nitroxymethyl)oxazolidone into 3-nitro-4,4-bis(nitromymethyl)oxazolz'done A nitrating mixture consisting of 5 cc. of 98 per cent nitric acid and 5 cc. of concentrated sulfuric acid was prepared. While stirring and maintaining a temperature of 510 C., 3.28 g. (0.014 mole) of 4,4-bis nitroxymethyl)oxazolidone was added. The reaction was heated to C. and kept at this temperature for one-half hour. After cooling, the solution was poured over 30 g. of cracked ice. The precipitate which formed was filtered and washed with water. After one recrystallization from 30 cc. of methyl alcohol there was obtained a solid (1.11 g.), 3-nitro-4,4-bis(nitroxymethyl) oxazolidone, melting at 121-2 0. Yield, 28 per cent.

It will be apparent to those skilled in the art that many variations, modifications and extensions of the processes described in the foregoing examples may be made without departing from the spirit and scope of the present invention. All such variations, modifications and extensions are to be understood as included within the scope of the appended claims.

We claim:

1. As a new composition of matter, N- (2- nitroxyalkyl) alkylnitramine.

2. As a new composition of matter, N-(2- nitroxyethyl) alkyl nitramine.

ALFRED T. BLOMQUIST. FRED T. FIEDOREK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date 1,560,427 Moran Nov. 3, 1925 FOREIGN PATENTS Number Country Date 350,293 Great Britain June 11, 1931 357,581 Great Britain Sept. 23, 1931 358,157 Great Britain Oct. 8, 1931 

